59,920 research outputs found
Photon counting compressive depth mapping
We demonstrate a compressed sensing, photon counting lidar system based on
the single-pixel camera. Our technique recovers both depth and intensity maps
from a single under-sampled set of incoherent, linear projections of a scene of
interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional
reconstructions are required to image a three-dimensional scene. We demonstrate
intensity imaging and depth mapping at 256 x 256 pixel transverse resolution
with acquisition times as short as 3 seconds. We also show novelty filtering,
reconstructing only the difference between two instances of a scene. Finally,
we acquire 32 x 32 pixel real-time video for three-dimensional object tracking
at 14 frames-per-second.Comment: 16 pages, 8 figure
Magnetic-Visual Sensor Fusion-based Dense 3D Reconstruction and Localization for Endoscopic Capsule Robots
Reliable and real-time 3D reconstruction and localization functionality is a
crucial prerequisite for the navigation of actively controlled capsule
endoscopic robots as an emerging, minimally invasive diagnostic and therapeutic
technology for use in the gastrointestinal (GI) tract. In this study, we
propose a fully dense, non-rigidly deformable, strictly real-time,
intraoperative map fusion approach for actively controlled endoscopic capsule
robot applications which combines magnetic and vision-based localization, with
non-rigid deformations based frame-to-model map fusion. The performance of the
proposed method is demonstrated using four different ex-vivo porcine stomach
models. Across different trajectories of varying speed and complexity, and four
different endoscopic cameras, the root mean square surface reconstruction
errors 1.58 to 2.17 cm.Comment: submitted to IROS 201
Depth Fields: Extending Light Field Techniques to Time-of-Flight Imaging
A variety of techniques such as light field, structured illumination, and
time-of-flight (TOF) are commonly used for depth acquisition in consumer
imaging, robotics and many other applications. Unfortunately, each technique
suffers from its individual limitations preventing robust depth sensing. In
this paper, we explore the strengths and weaknesses of combining light field
and time-of-flight imaging, particularly the feasibility of an on-chip
implementation as a single hybrid depth sensor. We refer to this combination as
depth field imaging. Depth fields combine light field advantages such as
synthetic aperture refocusing with TOF imaging advantages such as high depth
resolution and coded signal processing to resolve multipath interference. We
show applications including synthesizing virtual apertures for TOF imaging,
improved depth mapping through partial and scattering occluders, and single
frequency TOF phase unwrapping. Utilizing space, angle, and temporal coding,
depth fields can improve depth sensing in the wild and generate new insights
into the dimensions of light's plenoptic function.Comment: 9 pages, 8 figures, Accepted to 3DV 201
Background-Limited Imaging in the Near-Infrared with Warm InGaAs Sensors: Applications for Time-Domain Astronomy
We describe test observations made with a customized 640 x 512 pixel Indium
Gallium Arsenide (InGaAs) prototype astronomical camera on the 100" DuPont
telescope. This is the first test of InGaAs as a cost-effective alternative to
HgCdTe for research-grade astronomical observations. The camera exhibits an
instrument background of 113 e-/sec/pixel (dark + thermal) at an operating
temperature of -40C for the sensor, maintained by a simple thermo-electric
cooler. The optical train and mechanical structure float at ambient temperature
with no cold stop, in contrast to most IR instruments which must be cooled to
mitigate thermal backgrounds. Measurements of the night sky using a reimager
with plate scale of 0.4 arc seconds / pixel show that the sky flux in Y is
comparable to the dark current. At J the sky brightness exceeds dark current by
a factor of four, and hence dominates the noise budget. The sensor read noise
of ~43e- falls below sky+dark noise for exposures of t>7 seconds in Y and 3.5
seconds in J. We present test observations of several selected science targets,
including high-significance detections of a lensed Type Ia supernova, a type
IIb supernova, and a z=6.3 quasar. Deeper images are obtained for two local
galaxies monitored for IR transients, and a galaxy cluster at z=0.87. Finally,
we observe a partial transit of the hot JupiterHATS34b, demonstrating the
photometric stability required over several hours to detect a 1.2% transit
depth at high significance. A tiling of available larger-format sensors would
produce an IR survey instrument with significant cost savings relative to
HgCdTe-based cameras, if one is willing to forego the K band. Such a camera
would be sensitive for a week or more to isotropic emission from r-process
kilonova ejecta similar to that observed in GW170817, over the full 190 Mpc
horizon of Advanced LIGO's design sensitivity for neutron star mergers.Comment: 13 pages, 12 figures, submitted to A
RGB-D datasets using microsoft kinect or similar sensors: a survey
RGB-D data has turned out to be a very useful representation of an indoor scene for solving fundamental computer vision problems. It takes the advantages of the color image that provides appearance information of an object and also the depth image that is immune to the variations in color, illumination, rotation angle and scale. With the invention of the low-cost Microsoft Kinect sensor, which was initially used for gaming and later became a popular device for computer vision, high quality RGB-D data can be acquired easily. In recent years, more and more RGB-D image/video datasets dedicated to various applications have become available, which are of great importance to benchmark the state-of-the-art. In this paper, we systematically survey popular RGB-D datasets for different applications including object recognition, scene classification, hand gesture recognition, 3D-simultaneous localization and mapping, and pose estimation. We provide the insights into the characteristics of each important dataset, and compare the popularity and the difficulty of those datasets. Overall, the main goal of this survey is to give a comprehensive description about the available RGB-D datasets and thus to guide researchers in the selection of suitable datasets for evaluating their algorithms
- …